High energy charged particles may be detected when these particles strike a suitable scintillator material, such as certain plastics. The scintillator material emits photons that are typically at an ultraviolet (UV) wavelength when struck. Conventional paddle style scintillation radiation detectors include relatively large (i.e., 0.5 to 6 foot) plastic scintillators attached to photomultiplier tubes (PMTs) or silicon-based photodiodes. A “waveshifter” material with a dopant that re-emits the scintillator light at a wavelength that matches the sensitivity of the PMT or photodiode is added, which introduces dead space in the counter.
PMTs are delicate, high voltage vacuum tube detectors that generate a cascade of electrons when they receive incident light. Most conventional PMTs are at least eight inches long and exceed three inches in diameter. Such large, heavy parts that require high voltage do not lend themselves to space applications, for example. Furthermore, vacuum tube sensor operation becomes problematic outside of the standard temperature and pressure (STP) environment found on the surface of the Earth. This also makes these particle counters a poor fit for undersea and subterranean applications, such as deep sea exploration and drilling. Also, silicon photodiodes are extremely sensitive to temperature changes for operation with scintillators and require temperature stability. This does not work well in space, at high altitude, or in terrestrial environments where temperature varies significantly. Accordingly, an improved particle counter may be beneficial.